On this date in 1951, Albert Guay was hanged in Canada for one of the earliest commercial airline attacks — bombing a Canadian Pacific Airline flight to murder his wife.

Stuck in a loveless marriage with little recourse to divorce, Guay‘s loins burned for a young mistress.

He engaged a watchmaker colleague, Généreux Ruest, to make a bomb, and the latter’s sister, Marguerite Ruest-Pitre, to air freight it on the doomed plane. Both would maintain their innocence of the plot, but after Guay’s own conviction, he implicated both — possibly in an attempt to delay his own hanging.

A time bomb in the luggage hold of this airplane took 23 lives on September 9, 1949, for which three people were executed — and inspired a copycat crime with 44 more deaths and one more execution.

Guay had intended the plane to explode over the St. Lawrence River, eliminating the forensic evidence, but a slight delay before takeoff laid the damning debris over the land. The flight’s entire complement of four crew and nineteen passengers — including three top executives of the Kennecott Utah Copper Corporation — perished.

The crime had ample media attention both north and south of the Canada-U.S. border — flight still being something of a terrifying novelty for the general public. Guay’s purchase of life insurance for his wife on the day of the trip was not especially inculpatory, but a standard procedure for air travelers.